Making legend items start in new column in ArcGIS Pro?

Using ArcGIS Pro 2.3.0, youu can select 'Legend Arrangement Options':

Select 'Adjust Frame'.:

Then select the item from the legend that will go in a new column and return to the 'Element' settings, where a new option 'New Column' will have appeared. This functions like the 'Place item(s) in new column' setting in ArcMap:

This can be done in ArcGIS Pro 1.4 and I believe this is available even in 1.3.1.

1. Create a new legend.
2. Open the Formal Legend panel.
3. Click the Legend Arrangement Options button.

4. For Fitting Strategy, choose Adjust columns and font size. You can also specify the gap between columns under the Spacing section.

Note: if you choose Adjust Columns as your Fitting Strategy, then your legend will always have a new column for each item. However, I haven't found a property to specify the number of columns for the legend. You could work around this by resizing the legend item to force it to have a certain number of columns.

Your legend would look like this with the Adjust columns and font size strategy:

Your legend would look like this with the Adjust columns strategy: